name=input("what's your name?")
print("hello," +name+ "!")
# name前后的+可以省略吗，有什么用这里
# print("hello," name "!")
# 经验证不可以，否则提示name无效

from turtle import forward
from turtle import left
from turtle import right
from turtle import back
from turtle import penup
from turtle import pendown

forward(100)
left(120)
forward(100)

penup()     #这个函数括号里面不能有数值，否则就出现这样的错误提示 TypeError: penup() takes 0 positional arguments but 1 was given
forward(10)
pendown()

left(120)
forward(100)
